<!doctype html>
<html>
<head>
  <meta charset="utf-8">
  <title></title>
  <style type="text/css">
    html, body {
      margin: 0px;
      padding: 0px;
      width: 100%;
      height: 100%;
      font-family: "微软雅黑";
      font-size: 62.5%;
    }
    
    .boxDom {
      width: 100%;
      height: 100%;
      position: relative;
      overflow: hidden;
    }
    
    .idDom {
      width: 100%;
      height: 100px;
      background: #666;
      position: fixed;
      bottom: 0px;
    }
    
    .content {
      display: inline-block;
      width: 430px;
      height: 40px;
      position: absolute;
      left: 0px;
      right: 0px;
      top: 0px;
      bottom: 0px;
      margin: auto;
    }
    
    .title {
      display: inline;
      font-size: 4em;
      vertical-align: bottom;
      color: #fff;
    }
    
    .text {
      border: none;
      width: 300px;
      height: 30px;
      border-radius: 5px;
      font-size: 2.4em;
    }
    
    .btn {
      width: 60px;
      height: 30px;
      background: #f90000;
      border: none;
      color: #fff;
      font-size: 2.4em;
    }
    
    span {
      width: 300px;
      height: 40px;
      position: absolute;
      overflow: hidden;
      color: #000;
      font-size: 4em;
      line-height: 1.5em;
      cursor: pointer;
      white-space: nowrap;
    }
  
  </style>
</head>

<body>

<div class="boxDom" id="boxDom">
  <div class="idDom" id="idDom">
    <div class="content">
      <p class="title">吐槽:</p>
      <input type="text" class="text" id="text"/>
      <button type="button" class="btn" id="btn">发射</button>
    </div>
  </div>
</div>
</body>

<script src="jquery-1.12.4.js"></script>
<script>
  $(function () {
      $("#btn").click(function () {
          var colors=["red","green","hotpink","pink","cyna","yellowgreen"
          ,"purple","deepskyblue"]
          var randomColor=parseInt(Math.random()*colors.length)
          var randomTop=parseInt(Math.random()*400)
          $("<span></span>")
              .text($("#text").val())//设置内容
              .css("color",colors[randomColor])
              .css("left",1400)
              .css("top",randomTop)
              .animate({left:-400},10000,"linear",function(){
                  $(this).remove()
              })
              .appendTo($("#boxDom"));

           $("#text").val("")
      })
      $("#text").keyup(function (e) {
          if(e.keyCode==13){
              $("#btn").click();
          }
      });
  })

</script>
</html>
